computer monitor issues

I’ve been having a black flickering strip on the right side of my monitor all afternoon. It goes about a quarter of the way across, goes away for a while and sneaks back up on me. I did the windows troubleshooting deal for the monitor but it said it was working properly.
Two things that may or may not have a thing to do with the problem:
I started downloading a few objects (mostly recolors) for my Sims game from MTS2 yesterday so maybe it’s a general graphics issue?
Also, I’ve been dealing with ants over the past few weeks. It’s been several days since I battled them but maybe they got in there somewhere and screwed something up?

It’s the monitor. Luckily I kept my old one; just had to break it out of storage and dust it off. Still wondering why it quit on me though.

On some monitors the picture doubles back on it’s self, if the picture is adjusted too far over to a side. You get overlap. Try making the screen image smaller in size or by adjusting it to the left or right.